Important: Family member(s) who are going to live in Japan more than 3 months has to join health insurance and pension. If you join national health insurance and national pension, the following procedures must be completed within 14 days after the family member(s) arrives in Japan.

UEC full-time employee or fixed-term full time faculty member who works 40 hours/week or more: Personnel and Labor Affairs Office

UEC part-time employee who works less than 29 hours/week, JSPS Postdoctoral Research Fellow (JSPS Postdoctral Fellowship for Research in Japan) or unpaid researcher: Local municipal office

II. If you bring your family to Japan with a short-term stay visa (visiting relatives or acquaintances) to stay in Japan less than 90 days:

Apart from nationals and citizen of those countries or regions which have the Visa Exemption Arrangement with Japan, the short-term stay visa (visiting relatives or acquaintances) is required for your family to stay in Japan even it is less than 90 days. A visa applicant (i.e. your family) has to apply for the short-term stay visa (visiting relatives or acquaintances) *with all necessary documents at Japanese embassy or consulate where you reside. As a guarantor, you need to prepare necessary document as well and send them to the visa applicant by post.
*Short-term stay visa (Visiting relatives or acquaintances) is a visa for an applicant who has a purpose to come to Japan to visit his/her relatives or acquaintances for short-term. (If a visa applicant comes to Japan for sightseeing, but stay at the relative’s or friend’s house, he/she can apply for this visa type.) In this visa category, “relative” indicates a spouse who is in Japan and in the degree of consanguinity and affinity 3, as well as the relative in-law.

Required documents for short-term stay differ depending on the visa applicant’s nationality. Also, these documents may be changed or added by Ministry of Foreign Affairs.
Please make sure to check the following URL to confirm the information before you apply.

Reference: Ministry of Foreign Affairs “Short-Term Stay”

Note: A maximum period of short-term stay visa is 90 days. There are some cases that the granted period of stay is less than 90 days.